In normal-weight subjects, the efects of a high carbohydrate (hi-CHO) vs HIGH FAT (hi-FAT) diet/meal on lipoprotein lipase (LPL) responsiveness in adipose tissue (at) or skeletal muscle (sm)will predict weight stability vs weight gain over 5 yr and in obese subjects, the effects of a hi-CHO vs hi-FAT diet/meal on tissue-specific LPL responsiveness will predict weight stability of the obese weight vs additional weight gain over 5 yr.